Bleaching and coloring (or dyeing) of hair has become increasingly popular over the past years. Younger people may want to change the natural color of their hair to a more fashionable one, while older people may also use dyeing products to conceal gray hair. As a result there is an extremely large choice of available products for consumers to choose from. Often, the individual consumers find it difficult to determine which hair coloring product to choose to achieve their desired color.
Hair coloring products may be sold in packages displaying a coloring chart with three or more starting colors and three or more corresponding resulting colors. However, consumers have difficulties identifying which of the starting colors best matches their starting hair color and more choice of starting colors is desirable for a more accurate result. Furthermore consumers often do not trust the accuracy of the printed color chart on the carton.
Complicated systems have been designed in the past wherein the consumer inputs information about the starting color of his/her hair and the desired color, the system then matching this information with a commercial product that will provide the desired result. These systems can be implemented on a computer or via mechanical means such as cooperating wheels.
For example EP290327 discloses an apparatus for selecting a coloring product capable of achieving a desired hair color. The apparatus comprises a micro-processing unit, a memory bank relating to available coloring products, a keyboard for inputting information about the starting and the desired color into the micro-processing unit, and a printer connected to the micro-processing unit. The micro-processing unit is programmed to predict from the inputted information a suitable coloring product, whose reference is then printed on paper.
EP1147722 discloses a hair color advice system comprising a digital camera for taking a picture of a subject, a computer processing means and a computer screen. The computer processing means is programmed to analyze the picture taken, distinguish the hair area in the picture and electronically change the color of the hair area to a new color. The modified picture is displayed on the computer screen and, if the subject is satisfied by the displayed color, the processing means is used to predict a coloring product suitable for providing the desired color to the subject's hair.
U.S. Pat. No. 4,434,467 discloses a device for determining the hair coloring products to be used to change a subject's initial hair color to a desired hair color comprising an electronic data processing system.
WO01/87245 discloses a system for recommending a hair coloring product, said system comprising a colorimeter or spectrophotometer for analyzing the initial hair color of a subject and a computer system implemented with a color prediction model. The system is capable of identifying at least one achievable end hair color based upon said initial hair color and optionally other parameters such as hair damage, and is also capable of recommending a suitable coloring product for achieving any of the achievable hair color upon request from the subject.
EP1,240,845 discloses an apparatus for providing personalized advice regarding hair coloring.
It has now been found that consumers were often confused by the large choice of coloring products available in store and that selecting and trying a new coloring product is a stressful and sometimes disappointing experience. Consumers will often pick a coloring product on a shelf, spend a few minutes reading the information printed on the package to eventually put it back as the information displayed will leave them in doubt as to the result the product will give on their hair. Furthermore, consumers are often disappointed by the result of hair coloring and need to try several different products (typically 3–4) before finding a product providing their desired final hair color. There is therefore a need for a method of quickly and simply predicting the result of a coloration of a substrate such as hair by a specific coloring product.